Jenna Ladd | October 18, 2016

Flood mitigation efforts in the state thus far have centered around building levees, flood walls, and protecting utilities, but Iowa researchers have found that upstream structures like wetlands and detention pounds are an effective means of flood prevention. Sen. Rob Hogg of Cedar Rapids said that some lawmakers have acknowledged the need to ramp up these strategies, but the conversation is often buried by health care and education budget arguments. Hogg said, “If you can’t reach agreement over funding the basics, it’s really hard to get to the next level, to discuss funding water management.”

The increasing frequency of extreme rainfall may demand that flood mitigation take center stage at the capital. “We were hard-pressed to get 4-inch rainfalls 100 years ago, and now it’s very common,” said Jerry Schnoor, co-director at the University of Iowa’s Center for Global and Regional Environmental Research. Eugene Takle, director of the climate science program at Iowa State University, agreed, “In the Cedar River basin, we found the 100-year flood a century ago is now very likely to be a 25-year flood.” The Cedar basin’s record flood in 2008 had a $5 billion price tag.

Takle and other experts say these changes are primarily due to climate change. Rising greenhouse gases in the atmosphere allow it to hold more water vapor. “When you have more water vapor, you can expect more rain events,” he said. Takle’s data support this claim: atmospheric water vapor has increased by 31 percent in the winter months since 1970 and by 14 percent in the spring; average annual rainfall in Iowa has risen by 33 percent since 1970. Takle said, “This is consistent with what the climate models said would happen. The Midwest has experienced a big increase in extreme events.” According to NOAA National Centers for Environmental Information, Iowa has had 26 flood disasters with damages adding up to more than $1 billion since 1980.

Larry Weber, director at the University of IIHR – Hydroscience & Engineering, parent organization of the Iowa Flood Center, said that the loss of prairie potholes and wetlands, which can soak up heavy rainfalls, has contributed to these flooding events. He said, “We’ve taken away a lot of those natural storage areas.”

Iowa lawmakers passed a sales-tax funding plan in 2012 to provide $1.4 billion in flood prevention structures, but more funding is needed. Eight-nine towns and cities have identified $35 million in flood prevention structures that do not have funding. Some Iowa lawmakers are working to increase the sales tax by three-eighths of 1 cent in order to fund the Natural Resources and Outdoor Recreation Trust Fund, which would provide $180 million each year to restore wetlands, protect wildlife habitat, reduce runoff and improve trails, and more.

One and a half million dollars in federal supplemental aid money allocated to the Iowa Flood Center’s Iowa Watersheds Project after the 2008 flood has reduced flooding downstream by 15-20 percent in the Otter, Beaver and South Chequest watersheds. The center received $98 million in federal grant money this year for similar flood mitigation projects in 25 additional watersheds. Weber said, “We’re making great strides in the places where we work, we just need to be working in more places — whether it’s through our projects, or the work of other state and federal agencies, private landowners, and nonprofit groups.”